Knowing quite a few engineers and pilots really well, I would say listen to the engineer every time! If he says dont fly it, then dont.
BUT...I will emphasise the word ENGINEER.....not mechanics!
I have seen a few arguments on the flight deck over the years, i.e. the captain wants to take it, but the engineer doesn't want him to.
Pilots have FANTASTIC knowledge of the machines they fly, inside and out, but I would always listen to that chap in the overalls who is capable of completely re-building the thing!
Thats just my 2 pence worth..
